Modules quadratiques
is the category of spaces with filters: an object is a pair , a compact Hausdorff space and a filter of dense open subsets of . A morphism is a continuous function for which whenever . This category arises naturally from considerations in ordered algebra, e.g., Boolean algebra, lattice-ordered groups and rings, and from considerations in general topology, e.g., the theory of the absolute and other covers, locales, and frames, though we shall specifically address only one of these...